Generically, I agree with others that suggest just bringing a big power bank on a bike tour if it is a short tour instead of investing in the USB charging gear. But in my opinion, if you are touring for more than a week, then investing in the dyno powered USB charger makes sense. My last bike tour was five weeks and most of that time I was self sufficient for all my electric needs from the dynohub.
I used a Sinewave Revolution for about six years, was very happy with it, still have it. I think it is the best waterproofed charger out there.
https://www.sinewavecycles.com/produ...ave-revolution
But last summer I decided to buy the Cycle2Charge, it puts out about 50 percent more power than the Sinewave. I have not used it for touring yet, but so far I think it will be my new go to USB charger for touring. The Sinewave did not put out much more power than I needed on a tour for charging up GPS, headlamp (for my head in campsite), taillight batteries for my flasher, camera batteries, phone, etc. The Cycle2Charge should put out enough that I do not have to be obsessive about conserving my electric power.
https://www.cycle2charge.de/index.php/en/
I bought my Cycle2Charge from Amazon in Germany. They charge in Euros or will do the currency conversion for a small fee. I told them to charge my credit card in Euros because my card does not charge a fee for currency conversion. I think shipping was about two or three weeks total. But some credit cards in USA charge 3 percent fee for currency conversion.
https://www.amazon.de/Cycle2Charge-V...B¤cy=EUR
Peter White suggests that Supernova headlamp and taillight should be used together and not mixed with other brands. In other words, your taillight might not work with your headlamp. I have never used Supernova, so I do not have any more detail on this. I have only used B&M or Spanninga taillights with B&M or AXA headlamps, those brands all play well with each other.
I wrote up a description of how I wired up my lights and charger at this link if you are curious:
https://www.bikeforums.net/electroni...b-charger.html
I have bought a lot of bike stuff from Europe, you should not be nervous about buying from there. Shipping takes a bit more time, but generally you should not have any problems.